ERBB2 and breast carcinoma: The KATHERINE trial assigned patients with HER2-positive early breast cancer who had residual invasive disease in the breast or axilla at surgery after receiving adjuvant therapy containing taxane + trastuzumab to receive adjuvant T-DM1 or trastuzumab, and demonstrated that T-DM1 reduced by 50% to the risk of recurrence of invasive breast cancer or death but displayed more associated adverse events [79].